diff --git a/make/project.mk b/make/project.mk
index 4d84f21fef..a5e487b85c 100644
--- a/make/project.mk
+++ b/make/project.mk
@@ -45,6 +45,27 @@ $(warning "esp-idf build system only supports GNU Make versions 3.81 or newer. Y
 endif
 endif
 
+# make IDF_PATH a "real" absolute path
+# * works around the case where a shell character is embedded in the environment variable value.
+# * changes Windows-style C:/blah/ paths to MSYS/Cygwin style /c/blah
+export IDF_PATH:=$(realpath $(wildcard $(IDF_PATH)))
+
+ifndef IDF_PATH
+$(error IDF_PATH variable is not set to a valid directory.)
+endif
+
+ifneq ("$(IDF_PATH)","$(realpath $(wildcard $(IDF_PATH)))")
+# due to the way make manages variables, this is hard to account for
+#
+# if you see this error, do the shell expansion in the shell ie
+# make IDF_PATH=~/blah not make IDF_PATH="~/blah"
+$(error If IDF_PATH is overriden on command line, it must be an absolute path with no embedded shell special characters)
+endif
+
+ifneq ("$(IDF_PATH)","$(subst :,,$(IDF_PATH))")
+$(error IDF_PATH cannot contain colons. If overriding IDF_PATH on Windows, use Cygwin-style /c/dir instead of C:/dir)
+endif
+
 # disable built-in make rules, makes debugging saner
 MAKEFLAGS_OLD := $(MAKEFLAGS)
 MAKEFLAGS +=-rR
@@ -358,7 +379,7 @@ $(foreach component,$(TEST_COMPONENT_PATHS),$(eval $(call GenerateComponentTarge
 app-clean: $(addsuffix -clean,$(notdir $(COMPONENT_PATHS_BUILDABLE)))
 	$(summary) RM $(APP_ELF)
 	rm -f $(APP_ELF) $(APP_BIN) $(APP_MAP)
-	
+
 size: $(APP_ELF)
 	$(SIZE) $(APP_ELF)