diff --git a/bin/kaleidoscope-builder b/bin/kaleidoscope-builder
index 7f0f2d48..1e08dedc 100755
--- a/bin/kaleidoscope-builder
+++ b/bin/kaleidoscope-builder
@@ -379,9 +379,9 @@ compile () {
         fi
     fi
 
-    _CMD_CXX="${COMPILER_PREFIX}${CXX_COMPILER_BASENAME}${COMPILER_SUFFIX}"
-    _CMD_CC="${COMPILER_PREFIX}${C_COMPILER_BASENAME}${COMPILER_SUFFIX}"
-    _CMD_AR="${COMPILER_PREFIX}${AR_BASENAME}${COMPILER_SUFFIX}"
+    _CMD_CXX="${CXX:-${COMPILER_PREFIX}${CXX_COMPILER_BASENAME}${COMPILER_SUFFIX}}"
+    _CMD_CC="${CC:-${COMPILER_PREFIX}${C_COMPILER_BASENAME}${COMPILER_SUFFIX}}"
+    _CMD_AR="${AR:-${COMPILER_PREFIX}${AR_BASENAME}${COMPILER_SUFFIX}}"
 
     # SC2091: We do not care if quotes or backslashes are not respected.
     # SC2086: We want word splitting.