diff --git a/src/apps/terminal/AppearPrefView.cpp b/src/apps/terminal/AppearPrefView.cpp
index 6d96bea661..615305f8d2 100644
--- a/src/apps/terminal/AppearPrefView.cpp
+++ b/src/apps/terminal/AppearPrefView.cpp
@@ -211,10 +211,13 @@ IsFontUsable(const BFont &font)
 	if (font.IsFixed())
 		return true;
 	
+	//font_height fontHeight;
+	
 	// manually check if all applicable chars are the same width
 	char buffer[2] = { ' ', 0 };
 	int firstWidth = (int)ceilf(font.StringWidth(buffer));
-	
+	if (firstWidth <= 0)
+		return false;
 	for (int c = ' '+1; c <= 0x7e; c++) {
 		buffer[0] = c;
 		int width = (int)ceilf(font.StringWidth(buffer));