diff --git a/src/libm/e_exp.c b/src/libm/e_exp.c
index d8cd4a4..4d1e7d1 100644
--- a/src/libm/e_exp.c
+++ b/src/libm/e_exp.c
@@ -75,6 +75,10 @@
 #include "math_libm.h"
 #include "math_private.h"
 
+#ifdef __WATCOMC__ /* Watcom defines huge=__huge */
+#undef huge
+#endif
+
 static const double
 one	= 1.0,
 halF[2]	= {0.5,-0.5,},
diff --git a/src/libm/e_pow.c b/src/libm/e_pow.c
index cfd1dbf..a3d24ce 100644
--- a/src/libm/e_pow.c
+++ b/src/libm/e_pow.c
@@ -63,6 +63,10 @@
 #pragma warning ( disable : 4756 )
 #endif
 
+#ifdef __WATCOMC__ /* Watcom defines huge=__huge */
+#undef huge
+#endif
+
 static const double
 bp[] = {1.0, 1.5,},
 dp_h[] = { 0.0, 5.84962487220764160156e-01,}, /* 0x3FE2B803, 0x40000000 */
diff --git a/src/libm/s_atan.c b/src/libm/s_atan.c
index f664f0e..90fb6ab 100644
--- a/src/libm/s_atan.c
+++ b/src/libm/s_atan.c
@@ -60,6 +60,10 @@
   1.62858201153657823623e-02, /* 0x3F90AD3A, 0xE322DA11 */
 };
 
+#ifdef __WATCOMC__ /* Watcom defines huge=__huge */
+#undef huge
+#endif
+
 static const double
 one   = 1.0,
 huge   = 1.0e300;
diff --git a/src/libm/s_floor.c b/src/libm/s_floor.c
index 3f9a5ce..14738aa 100644
--- a/src/libm/s_floor.c
+++ b/src/libm/s_floor.c
@@ -24,6 +24,10 @@
 #include "math_libm.h"
 #include "math_private.h"
 
+#ifdef __WATCOMC__ /* Watcom defines huge=__huge */
+#undef huge
+#endif
+
 static const double huge = 1.0e300;
 
 double floor(double x)
diff --git a/src/libm/s_scalbn.c b/src/libm/s_scalbn.c
index 6bb7192..dac2feb 100644
--- a/src/libm/s_scalbn.c
+++ b/src/libm/s_scalbn.c
@@ -20,6 +20,10 @@
 #include "math_private.h"
 #include <limits.h>
 
+#ifdef __WATCOMC__ /* Watcom defines huge=__huge */
+#undef huge
+#endif
+
 static const double
 two54  = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */
 twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */