diff --git a/TouchGFX/config/gcc/app.mk b/TouchGFX/config/gcc/app.mk
index 6a5485a..7244f42 100644
--- a/TouchGFX/config/gcc/app.mk
+++ b/TouchGFX/config/gcc/app.mk
@@ -6,3 +6,9 @@ touchgfx_path := ../Middlewares/ST/touchgfx
 touchgfx_env := C:/TouchGFX/4.22.0/env
 # Optional additional compiler flags
 user_cflags := -DUSE_BPP=16 -std=gnu++1z -Wno-cast-qual -Wno-missing-declarations -Wno-format-truncation -Wno-unused-variable
+
+# MINGW is annoying and for some reason replaces /z/path with z:/path in
+# ADDITIONAL_SOURCES. Since TouchGFXDesigner completely overwrites the generated
+# Makefile, we can't fix it there -- but the generated makefile includes this
+# file, so we can fix it here.
+ADDITIONAL_SOURCES := $(call subst_drivename,$(ADDITIONAL_SOURCES))
diff --git a/TouchGFX/simulator/gcc/Makefile b/TouchGFX/simulator/gcc/Makefile
index 1481c1b..a84ea35 100644
--- a/TouchGFX/simulator/gcc/Makefile
+++ b/TouchGFX/simulator/gcc/Makefile
@@ -12,6 +12,12 @@ makefile_path := $(call qs,$(dir $(call sq,$(abspath $(call sq,$(makefile_name))
 
 # Get path where the Application is
 application_path := $(call qs,$(abspath $(call sq,$(makefile_path)../..)))
+# Under Windows (MINGW32), the path is returned as e.g. z:/path/to/application
+# Since the path may show up as a target in the Makefile, we can't have a colon
+# in it. So we replace z:/ with /z/ to avoid this.
+subst_drivename = $(shell echo $(1) | sed -e 's!^\([a-zA-Z]\):/!/\1/!')
+export subst_drivename
+application_path := $(call subst_drivename,$(application_path))
 
 .PHONY: clean assets all
 
@@ -29,6 +35,7 @@ export ADDITIONAL_SOURCES ADDITIONAL_INCLUDE_PATHS ADDITIONAL_LIBRARY_PATHS ADDI
 all: $(filter assets,$(MAKECMDGOALS))
 all assets: $(filter clean,$(MAKECMDGOALS))
 all clean assets:
+	@echo ADDITIONAL_SOURCES: $(ADDITIONAL_SOURCES)
 	@$(MAKE) -r -f generated/simulator/gcc/Makefile -s $(MFLAGS) $@ -C "$(application_path)"
 endif