diff --git a/ueforth/Makefile b/ueforth/Makefile
index b1b6d0d..5088534 100644
--- a/ueforth/Makefile
+++ b/ueforth/Makefile
@@ -26,7 +26,7 @@ WINDOWS = $(OUT)/windows
 ESP32 = $(OUT)/esp32
 DEPLOY = $(OUT)/deploy
 
-CFLAGS_COMMON = -O2 -I ./ -I $(OUT)
+CFLAGS_COMMON = -std=c++11 -O2 -I ./ -I $(OUT)
 
 CFLAGS_MINIMIZE = \
                 -s \
@@ -185,7 +185,7 @@ $(GEN)/esp32_boot.h: common/source_to_string.js $(ESP32_BOOT) | $(GEN)
 	$< boot $(VERSION) $(REVISION) $(ESP32_BOOT) >$@
 
 $(GEN)/dump_web_opcodes: web/dump_web_opcodes.c common/opcodes.h | $(GEN)
-	$(CC) $(CFLAGS) $< -o $@
+	$(CXX) $(CFLAGS) $< -o $@
 
 $(GEN)/web_cases.js: $(GEN)/dump_web_opcodes | $(GEN)
 	$< cases >$@
@@ -253,7 +253,7 @@ $(POSIX)/ueforth: \
     common/interp.h \
     common/core.h \
     $(GEN)/posix_boot.h | $(POSIX)
-	$(CC) $(CFLAGS) $< -o $@ $(LIBS)
+	$(CXX) $(CFLAGS) $< -o $@ $(LIBS)
 	strip $(STRIP_ARGS) $@
 
 # ---- WINDOWS ----
diff --git a/ueforth/common/calls.h b/ueforth/common/calls.h
index f974b75..82fd682 100644
--- a/ueforth/common/calls.h
+++ b/ueforth/common/calls.h
@@ -15,7 +15,13 @@
 #ifndef CALLTYPE
 # define CALLTYPE
 #endif
+
+#ifdef __cplusplus
+typedef cell_t (CALLTYPE *call_t)(...);
+#else
 typedef cell_t (CALLTYPE *call_t)();
+#endif
+
 #define ct0 ((call_t) n0)
 
 #define CALLING_OPCODE_LIST \
diff --git a/ueforth/common/core.h b/ueforth/common/core.h
index 0fb8ebb..2cd585d 100644
--- a/ueforth/common/core.h
+++ b/ueforth/common/core.h
@@ -56,7 +56,7 @@ static cell_t convert(const char *pos, cell_t n, cell_t base, cell_t *ret) {
       d -= 7;
       if (d < 10) { return 0; }
     }
-    if (d >= base) { return 0; }
+    if (d >= (uintptr_t) base) { return 0; }
     *ret = *ret * base + d;
     ++pos;
   }
diff --git a/ueforth/common/source_to_string.js b/ueforth/common/source_to_string.js
index fb80a93..990c51e 100755
--- a/ueforth/common/source_to_string.js
+++ b/ueforth/common/source_to_string.js
@@ -40,12 +40,7 @@ for (var i = 5; i < process.argv.length; i++) {
 
 source = source.replace('{{VERSION}}', version);
 source = source.replace('{{REVISION}}', revision);
-source = source.replace(/\\/g, '\\\\');
-source = source.replace(/["]/g, '\\"');
-source = '"' + source.split('\n').join('\\n"\n"') + '\\n"';
-source = source.replace(/["]  ["]/g, '');
-source = source.replace(/["] [(] ([^)]*)[)] ["]/g, '// $1');
 
-source = 'const char ' + name + '[] =\n' + source + ';\n';
+source = 'const char ' + name + '[] = R"""(\n' + source + ')""";\n';
 
 process.stdout.write(source);
diff --git a/ueforth/posix/posix_main.c b/ueforth/posix/posix_main.c
index 1112356..e80d89c 100644
--- a/ueforth/posix/posix_main.c
+++ b/ueforth/posix/posix_main.c
@@ -24,7 +24,7 @@
 #define STACK_CELLS (8 * 1024)
 
 #define PLATFORM_OPCODE_LIST \
-  Y(DLSYM, tos = (cell_t) dlsym(a1, a0); --sp) \
+  Y(DLSYM, tos = (cell_t) dlsym(a1, c0); --sp) \
   FLOATING_POINT_LIST \
   CALLING_OPCODE_LIST \