diff --git a/core/src/main/java/org/lflang/generator/CodeBuilder.java b/core/src/main/java/org/lflang/generator/CodeBuilder.java
index 9fe82e46fd..af82d70512 100644
--- a/core/src/main/java/org/lflang/generator/CodeBuilder.java
+++ b/core/src/main/java/org/lflang/generator/CodeBuilder.java
@@ -126,7 +126,8 @@ public void prSourceLineNumber(EObject eObject, boolean suppress) {
         }
       }
       // Extract the filename from eResource, an astonishingly difficult thing to do.
-      String filePath = CommonPlugin.resolve(eObject.eResource().getURI()).path();
+      String filePath =
+          CommonPlugin.resolve(eObject.eResource().getURI()).path().replace("\\", "\\\\");
       pr("#line " + (node.getStartLine() + offset) + " \"" + filePath + "\"");
     }
   }
@@ -558,7 +559,11 @@ public CodeMap writeToFile(String path) throws IOException {
     for (var line : (Iterable<String>) () -> s.lines().iterator()) {
       lineNumber++;
       if (line.contains(END_SOURCE_LINE_NUMBER_TAG) && !path.endsWith(".ino")) {
-        out.append("#line ").append(lineNumber).append(" \"").append(path).append("\"");
+        out.append("#line ")
+            .append(lineNumber)
+            .append(" \"")
+            .append(path.replace("\\", "\\\\"))
+            .append("\"");
       } else {
         out.append(line);
       }
diff --git a/core/src/main/resources/lib/c/reactor-c b/core/src/main/resources/lib/c/reactor-c
index aaa38d8cbb..b67cdadf98 160000
--- a/core/src/main/resources/lib/c/reactor-c
+++ b/core/src/main/resources/lib/c/reactor-c
@@ -1 +1 @@
-Subproject commit aaa38d8cbb6155fd3d25bc50c432de3423396473
+Subproject commit b67cdadf9881346bf8693d245c4bc48dec68150a