diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index 7c581543da..e419a4d541 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -492,7 +492,10 @@ cmNinjaTargetGenerator
     cmLocalGenerator::RuleVariables compileObjectVars;
     std::string lang = language;
     compileObjectVars.Language = lang.c_str();
-    compileObjectVars.Source = sourceFileName.c_str();
+    std::string escapedSourceFileName =
+      this->LocalGenerator->ConvertToOutputFormat(
+        sourceFileName.c_str(), cmLocalGenerator::SHELL);
+    compileObjectVars.Source = escapedSourceFileName.c_str();
     compileObjectVars.Object = objectFileName.c_str();
     compileObjectVars.Flags = vars["FLAGS"].c_str();
     compileObjectVars.Defines = vars["DEFINES"].c_str();