diff --git a/gn/sksl_tests.gni b/gn/sksl_tests.gni
index ab6ac8b..b357734 100644
--- a/gn/sksl_tests.gni
+++ b/gn/sksl_tests.gni
@@ -637,6 +637,16 @@
   "/sksl/runtime_errors/ProgramTooLarge_NestedLoops.rts",
   "/sksl/runtime_errors/ProgramTooLarge_SplitLoops.rts",
   "/sksl/runtime_errors/ProgramTooLarge_StackDepth.rts",
+  "/sksl/runtime_errors/ReservedNameISampler2D.rts",
+  "/sksl/runtime_errors/ReservedNameSampler.rts",
+  "/sksl/runtime_errors/ReservedNameSampler1D.rts",
+  "/sksl/runtime_errors/ReservedNameSampler2D.rts",
+  "/sksl/runtime_errors/ReservedNameSampler2DRect.rts",
+  "/sksl/runtime_errors/ReservedNameSampler3D.rts",
+  "/sksl/runtime_errors/ReservedNameSamplerExternalOES.rts",
+  "/sksl/runtime_errors/ReservedNameSubpassInput.rts",
+  "/sksl/runtime_errors/ReservedNameSubpassInputMS.rts",
+  "/sksl/runtime_errors/ReservedNameTexture2D.rts",
   "/sksl/runtime_errors/UnsupportedTypeFragmentProcessor.rts",
   "/sksl/runtime_errors/UnsupportedTypeSampler.rts",
   "/sksl/runtime_errors/UnsupportedTypeTexture.rts",
diff --git a/resources/sksl/runtime_errors/ReservedNameISampler2D.rts b/resources/sksl/runtime_errors/ReservedNameISampler2D.rts
new file mode 100644
index 0000000..8e1c7a9
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameISampler2D.rts
@@ -0,0 +1 @@
+int isampler2D;
diff --git a/resources/sksl/runtime_errors/ReservedNameSampler.rts b/resources/sksl/runtime_errors/ReservedNameSampler.rts
new file mode 100644
index 0000000..6e17057
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSampler.rts
@@ -0,0 +1 @@
+int sampler;
diff --git a/resources/sksl/runtime_errors/ReservedNameSampler1D.rts b/resources/sksl/runtime_errors/ReservedNameSampler1D.rts
new file mode 100644
index 0000000..c3406a2
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSampler1D.rts
@@ -0,0 +1 @@
+int sampler1D;
diff --git a/resources/sksl/runtime_errors/ReservedNameSampler2D.rts b/resources/sksl/runtime_errors/ReservedNameSampler2D.rts
new file mode 100644
index 0000000..1da7d63
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSampler2D.rts
@@ -0,0 +1 @@
+int sampler2D;
diff --git a/resources/sksl/runtime_errors/ReservedNameSampler2DRect.rts b/resources/sksl/runtime_errors/ReservedNameSampler2DRect.rts
new file mode 100644
index 0000000..fce4ef2
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSampler2DRect.rts
@@ -0,0 +1 @@
+int sampler2DRect;
diff --git a/resources/sksl/runtime_errors/ReservedNameSampler3D.rts b/resources/sksl/runtime_errors/ReservedNameSampler3D.rts
new file mode 100644
index 0000000..67f35af
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSampler3D.rts
@@ -0,0 +1 @@
+int sampler3D;
diff --git a/resources/sksl/runtime_errors/ReservedNameSamplerExternalOES.rts b/resources/sksl/runtime_errors/ReservedNameSamplerExternalOES.rts
new file mode 100644
index 0000000..7c25094
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSamplerExternalOES.rts
@@ -0,0 +1 @@
+int samplerExternalOES;
diff --git a/resources/sksl/runtime_errors/ReservedNameSubpassInput.rts b/resources/sksl/runtime_errors/ReservedNameSubpassInput.rts
new file mode 100644
index 0000000..d72bf43
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSubpassInput.rts
@@ -0,0 +1 @@
+int subpassInput;
diff --git a/resources/sksl/runtime_errors/ReservedNameSubpassInputMS.rts b/resources/sksl/runtime_errors/ReservedNameSubpassInputMS.rts
new file mode 100644
index 0000000..c139777
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameSubpassInputMS.rts
@@ -0,0 +1 @@
+int subpassInputMS;
diff --git a/resources/sksl/runtime_errors/ReservedNameTexture2D.rts b/resources/sksl/runtime_errors/ReservedNameTexture2D.rts
new file mode 100644
index 0000000..a632412
--- /dev/null
+++ b/resources/sksl/runtime_errors/ReservedNameTexture2D.rts
@@ -0,0 +1 @@
+int texture2D;
diff --git a/src/sksl/SkSLCompiler.cpp b/src/sksl/SkSLCompiler.cpp
index 1b18daf..4acf300 100644
--- a/src/sksl/SkSLCompiler.cpp
+++ b/src/sksl/SkSLCompiler.cpp
@@ -243,7 +243,7 @@
 }
 
 static void add_glsl_type_aliases(SkSL::SymbolTable* symbols, const SkSL::BuiltinTypes& types) {
-    // Add some aliases to the runtime effect modules so that it's friendlier, and more like GLSL
+    // Add some aliases to the runtime effect modules so that it's friendlier, and more like GLSL.
     symbols->addAlias("vec2", types.fFloat2.get());
     symbols->addAlias("vec3", types.fFloat3.get());
     symbols->addAlias("vec4", types.fFloat4.get());
@@ -259,6 +259,12 @@
     symbols->addAlias("mat2", types.fFloat2x2.get());
     symbols->addAlias("mat3", types.fFloat3x3.get());
     symbols->addAlias("mat4", types.fFloat4x4.get());
+
+    // Alias every private type to "invalid". This will prevent code from using built-in names like
+    // `sampler2D` as variable names.
+    for (BuiltinTypePtr privateType : kPrivateTypes) {
+        symbols->addAlias((types.*privateType)->name(), types.fInvalid.get());
+    }
 }
 
 const ParsedModule& Compiler::loadPublicModule() {
diff --git a/src/sksl/ir/SkSLVarDeclarations.cpp b/src/sksl/ir/SkSLVarDeclarations.cpp
index 5a74b77..2aaf662 100644
--- a/src/sksl/ir/SkSLVarDeclarations.cpp
+++ b/src/sksl/ir/SkSLVarDeclarations.cpp
@@ -39,6 +39,10 @@
 
 void VarDeclaration::ErrorCheck(const Context& context, int line, const Modifiers& modifiers,
         const Type* baseType, Variable::Storage storage) {
+    if (*baseType == *context.fTypes.fInvalid) {
+        context.fErrors->error(line, "invalid type");
+        return;
+    }
     if (context.fConfig->strictES2Mode() && baseType->isArray()) {
         context.fErrors->error(line, "array size must appear after variable name");
     }
diff --git a/tests/sksl/runtime_errors/ReservedNameISampler2D.skvm b/tests/sksl/runtime_errors/ReservedNameISampler2D.skvm
new file mode 100644
index 0000000..e0d3619
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameISampler2D.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'isampler2D'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSampler.skvm b/tests/sksl/runtime_errors/ReservedNameSampler.skvm
new file mode 100644
index 0000000..4bce878
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSampler.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSampler1D.skvm b/tests/sksl/runtime_errors/ReservedNameSampler1D.skvm
new file mode 100644
index 0000000..70264fd
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSampler1D.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler1D'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSampler2D.skvm b/tests/sksl/runtime_errors/ReservedNameSampler2D.skvm
new file mode 100644
index 0000000..d8fbc3a
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSampler2D.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler2D'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSampler2DRect.skvm b/tests/sksl/runtime_errors/ReservedNameSampler2DRect.skvm
new file mode 100644
index 0000000..f0d4429
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSampler2DRect.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler2DRect'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSampler3D.skvm b/tests/sksl/runtime_errors/ReservedNameSampler3D.skvm
new file mode 100644
index 0000000..e984d6a
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSampler3D.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'sampler3D'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSamplerExternalOES.skvm b/tests/sksl/runtime_errors/ReservedNameSamplerExternalOES.skvm
new file mode 100644
index 0000000..99baf0a
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSamplerExternalOES.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'samplerExternalOES'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSubpassInput.skvm b/tests/sksl/runtime_errors/ReservedNameSubpassInput.skvm
new file mode 100644
index 0000000..c19fa4f
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSubpassInput.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'subpassInput'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameSubpassInputMS.skvm b/tests/sksl/runtime_errors/ReservedNameSubpassInputMS.skvm
new file mode 100644
index 0000000..e61ed93
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameSubpassInputMS.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'subpassInputMS'
+1 error
diff --git a/tests/sksl/runtime_errors/ReservedNameTexture2D.skvm b/tests/sksl/runtime_errors/ReservedNameTexture2D.skvm
new file mode 100644
index 0000000..7ef55ad
--- /dev/null
+++ b/tests/sksl/runtime_errors/ReservedNameTexture2D.skvm
@@ -0,0 +1,4 @@
+### Compilation failed:
+
+error: 1: expected an identifier, but found type 'texture2D'
+1 error
diff --git a/tests/sksl/runtime_errors/UnsupportedTypeSampler.skvm b/tests/sksl/runtime_errors/UnsupportedTypeSampler.skvm
index b44c950..703c4fe 100644
--- a/tests/sksl/runtime_errors/UnsupportedTypeSampler.skvm
+++ b/tests/sksl/runtime_errors/UnsupportedTypeSampler.skvm
@@ -1,6 +1,4 @@
 ### Compilation failed:
 
-error: 1: no type named 'sampler2D'
-error: 1: no type named 's'
-error: 1: expected a declaration, but found ';'
-3 errors
+error: 1: invalid type
+1 error
diff --git a/tests/sksl/runtime_errors/UnsupportedTypeTexture.skvm b/tests/sksl/runtime_errors/UnsupportedTypeTexture.skvm
index 108bab9..703c4fe 100644
--- a/tests/sksl/runtime_errors/UnsupportedTypeTexture.skvm
+++ b/tests/sksl/runtime_errors/UnsupportedTypeTexture.skvm
@@ -1,6 +1,4 @@
 ### Compilation failed:
 
-error: 1: no type named 'texture2D'
-error: 1: no type named 's'
-error: 1: expected a declaration, but found ';'
-3 errors
+error: 1: invalid type
+1 error