diff --git a/Makefile b/Makefile
index aaa6d8fc..73f2bc0d 100644
--- a/Makefile
+++ b/Makefile
@@ -106,9 +106,16 @@ $(OUT)/%.o: %.c
 	$(Q)$(CC) -o $@ $(CFLAGS) -c -MMD -MF $@.d $<
 
 SHELL_HACK := $(shell mkdir -p $(OUT) $(OUT)/$(SRCDIR) $(OUT)/tests)
-$(OUT)/libc.inc: $(OUT)/inliner $(LIBDIR)/c.c
+
+$(OUT)/norm-lf: tools/norm-lf.c
+	$(VECHO) "  CC+LD\t$@\n"
+	$(Q)$(CC) $(CFLAGS) -o $@ $^
+
+$(OUT)/libc.inc: $(OUT)/inliner $(OUT)/norm-lf $(LIBDIR)/c.c
 	$(VECHO) "  GEN\t$@\n"
-	$(Q)$(OUT)/inliner $(LIBDIR)/c.c $@
+	$(Q)$(OUT)/norm-lf $(LIBDIR)/c.c $(OUT)/c.normalized.c
+	$(Q)$(OUT)/inliner $(OUT)/c.normalized.c $@
+	$(Q)$(RM) $(OUT)/c.normalized.c
 
 $(OUT)/inliner: tools/inliner.c
 	$(VECHO) "  CC+LD\t$@\n"
@@ -146,7 +153,7 @@ clean:
 	-$(RM) $(OUT)/libc.inc
 
 distclean: clean
-	-$(RM) $(OUT)/inliner $(OUT)/target $(SRCDIR)/codegen.c config $(BUILD_SESSION)
+	-$(RM) $(OUT)/inliner $(OUT)/norm-lf $(OUT)/target $(SRCDIR)/codegen.c config $(BUILD_SESSION)
 	-$(RM) DOM.dot CFG.dot
 
 -include $(deps)
diff --git a/tools/inliner.c b/tools/inliner.c
index 03a4483b..7c632026 100644
--- a/tools/inliner.c
+++ b/tools/inliner.c
@@ -10,6 +10,9 @@
  * The inliner is used at build-time, and developers can use the
  * "inline C" feature to implement target-specific parts such as
  * C runtime and essential libraries.
+ *
+ * Note: Input files are preprocessed by norm-lf tool to ensure
+ * consistent LF (Unix) line endings before processing.
  */
 
 #include <stdbool.h>
@@ -110,7 +113,10 @@ void write_line(char *src)
 {
     write_str("  __c(\"");
     for (int i = 0; src[i]; i++) {
-        if (src[i] == '\"') {
+        if (src[i] == '\\') {
+            write_char('\\');
+            write_char('\\');
+        } else if (src[i] == '\"') {
             write_char('\\');
             write_char('\"');
         } else if (src[i] != '\n') {
diff --git a/tools/norm-lf.c b/tools/norm-lf.c
new file mode 100644
index 00000000..74589ced
--- /dev/null
+++ b/tools/norm-lf.c
@@ -0,0 +1,85 @@
+/*
+ * Convert all line endings to LF (Unix style)
+ *
+ * This tool ensures consistent line endings before processing with inliner.
+ * It converts CR-only (old Mac) and CRLF (Windows) to LF (Unix).
+ */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[])
+{
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <input> <output>\n", argv[0]);
+        return 1;
+    }
+
+    FILE *input = fopen(argv[1], "rb");
+    if (!input) {
+        fprintf(stderr, "Error: Cannot open input file '%s'\n", argv[1]);
+        return 1;
+    }
+
+    FILE *output = fopen(argv[2], "wb");
+    if (!output) {
+        fprintf(stderr, "Error: Cannot create output file '%s'\n", argv[2]);
+        fclose(input);
+        return 1;
+    }
+
+    int c;
+    int prev_cr = 0;
+    bool has_crlf = false;
+    bool has_lf = false;
+    bool has_cr_only = false;
+
+    while ((c = fgetc(input)) != EOF) {
+        if (c == '\r') {
+            /* Mark that we saw a CR, but don't output it yet */
+            prev_cr = 1;
+        } else if (c == '\n') {
+            if (prev_cr) {
+                /* CRLF sequence - output single LF */
+                has_crlf = true;
+            } else {
+                /* LF only */
+                has_lf = true;
+            }
+            fputc('\n', output);
+            prev_cr = 0;
+        } else {
+            if (prev_cr) {
+                /* CR not followed by LF - convert to LF */
+                fputc('\n', output);
+                has_cr_only = true;
+            }
+            fputc(c, output);
+            prev_cr = 0;
+        }
+    }
+
+    /* Handle CR at end of file */
+    if (prev_cr) {
+        fputc('\n', output);
+        has_cr_only = true;
+    }
+
+    fclose(input);
+    fclose(output);
+
+    /* Report what was found and converted */
+    if (has_cr_only) {
+        fprintf(stderr,
+                "Warning: Converted CR-only line endings to LF in '%s'\n",
+                argv[1]);
+    }
+    if ((has_crlf && has_lf) || (has_crlf && has_cr_only) ||
+        (has_lf && has_cr_only)) {
+        fprintf(stderr, "Warning: Converted mixed line endings to LF in '%s'\n",
+                argv[1]);
+    }
+
+    return 0;
+}