diff --git a/TextEditor.cpp b/TextEditor.cpp
index 2093ce1..cddb6ca 100644
--- a/TextEditor.cpp
+++ b/TextEditor.cpp
@@ -266,7 +266,7 @@
 		{
 			cumulatedStringWidth[1] = cumulatedStringWidth[0];
 			cumulatedString += line[columnCoord].mChar;
-			cumulatedStringWidth[0] = ImGui::CalcTextSize(cumulatedString.c_str()).x;
+			cumulatedStringWidth[0] = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, cumulatedString.c_str(), nullptr, nullptr).x;
 			columnWidth = (cumulatedStringWidth[0] - cumulatedStringWidth[1]);
 			columnCoord++;
 		}
@@ -615,7 +615,7 @@
 void TextEditor::Render()
 {
 	/* Compute mCharAdvance regarding to scaled font size (Ctrl + mouse wheel)*/
-	const float fontSize = ImGui::CalcTextSize("#").x;
+	const float fontSize = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, "#", nullptr, nullptr).x;
 	mCharAdvance = ImVec2(fontSize, ImGui::GetTextLineHeightWithSpacing() * mLineSpacing);
 
 	/* Update palette with the current alpha from style */
@@ -650,12 +650,12 @@
 	// Deduce mTextStart by evaluating mLines size (global lineMax) plus two spaces as text width
 	char buf[16];
 	snprintf(buf, 16, " %d ", globalLineMax);
-	mTextStart = ImGui::CalcTextSize(buf).x + mLeftMargin;
+	mTextStart = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, buf, nullptr, nullptr).x + mLeftMargin;
 
 	if (!mLines.empty())
 	{
 		auto fontScale = ImGui::GetFontSize() / ImGui::GetFont()->FontSize;
-		float spaceSize = ImGui::CalcTextSize(" ").x + 1.0f * fontScale;
+		float spaceSize = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, " ", nullptr, nullptr).x;
 
 		while (lineNo <= lineMax)
 		{
@@ -720,7 +720,8 @@
 
 			// Draw line number (right aligned)
 			snprintf(buf, 16, "%d  ", lineNo + 1);
-			auto lineNoWidth = ImGui::CalcTextSize(buf).x;
+			
+			auto lineNoWidth = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, buf, nullptr, nullptr).x;
 			drawList->AddText(ImVec2(lineStartScreenPos.x + mTextStart - lineNoWidth, lineStartScreenPos.y), mPalette[(int)PaletteIndex::LineNumber], buf);
 
 			// Highlight the current line (where the cursor is)
@@ -766,8 +767,8 @@
 				{
 					const ImVec2 newOffset(textScreenPos.x + bufferOffset.x, textScreenPos.y + bufferOffset.y);
 					drawList->AddText(newOffset, prevColor, buffer.c_str());
-					auto textSize = ImGui::CalcTextSize(buffer.c_str());
-					bufferOffset.x += textSize.x + 1.0f * fontScale;
+					auto textSize = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, buffer.c_str(), nullptr, nullptr);
+					bufferOffset.x += textSize.x;
 					buffer.clear();
 				}
 				prevColor = color;
@@ -1972,7 +1973,7 @@
 	auto& line = mLines[aFrom.mLine];
 	float distance = 0.0f;
 	auto fontScale = ImGui::GetFontSize() / ImGui::GetFont()->FontSize;
-	float spaceSize = ImGui::CalcTextSize(" ").x + 1.0f * fontScale;
+	float spaceSize = ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, " ", nullptr, nullptr).x;
 	for (size_t it = 0u; it < line.size() && it < (unsigned)aFrom.mColumn; ++it)
 	{
 		if (line[it].mChar == '\t')
@@ -1984,7 +1985,7 @@
 			char tempCString[2];
 			tempCString[0] = line[it].mChar;
 			tempCString[1] = '\0';
-			distance += ImGui::CalcTextSize(tempCString).x + 1.0f * fontScale;
+			distance += ImGui::GetFont()->CalcTextSizeA(ImGui::GetFontSize(), FLT_MAX, -1.0f, tempCString, nullptr, nullptr).x;
 		}
 	}