diff --git a/Makefile b/Makefile
index 90201847..ee480e03 100644
--- a/Makefile
+++ b/Makefile
@@ -53,7 +53,7 @@ vendor/coq:
 vendor/coq/config/coq_config.ml: vendor/coq
 	EPATH=$(shell pwd) \
 	&& cd vendor/coq \
-	&& ./configure -no-ask -prefix "$$EPATH/_build/install/default/" \
+	&& ./configure -debug -no-ask -prefix "$$EPATH/_build/install/default/" \
 	        -libdir "$$EPATH/_build/install/default/lib/coq" \
 		-native-compiler no \
 	&& cp theories/dune.disabled theories/dune \
@@ -66,7 +66,7 @@ vendor/coq/config/coq_config.ml: vendor/coq
 winconfig:
 	EPATH=$(shell cygpath -am .) \
 	&& cd vendor/coq \
-	&& ./configure -no-ask -prefix "$$EPATH\\_build\\install\\default\\" \
+	&& ./configure -debug -no-ask -prefix "$$EPATH\\_build\\install\\default\\" \
 	        -libdir "$$EPATH\\_build\\install\\default\\lib\\coq\\" \
 		-native-compiler no \
 	&& cp theories/dune.disabled theories/dune \
diff --git a/vendor/coq b/vendor/coq
index 6a2431e6..1f591d90 160000
--- a/vendor/coq
+++ b/vendor/coq
@@ -1 +1 @@
-Subproject commit 6a2431e6fa1f4a0bbee6d98c3b709aca781061d5
+Subproject commit 1f591d90a4c7bb24fcf22db9ba9ebbdc22b4af0d