diff --git a/Makefile b/Makefile
index 6394c42a5c3cd9ecfa57864c33cf15f87b0549cc..7bfa06f89a5c19f9b279f65875196f870b6f88c7 100644
--- a/Makefile
+++ b/Makefile
@@ -3,14 +3,6 @@ ifeq ($(Y), 1)
 	YFLAG=-y
 endif
 
-# Determine Coq version
-COQ_VERSION=$(shell coqc --version | egrep -o 'version 8.[0-9]' | egrep -o '8.[0-9]')
-COQ_MAKEFILE_FLAGS ?=
-
-ifeq ($(COQ_VERSION), 8.6)
-	COQ_MAKEFILE_FLAGS += -arg -w -arg -notation-overridden,-redundant-canonical-projection,-several-object-files
-endif
-
 # Forward most targets to Coq makefile (with some trick to make this phony)
 %: Makefile.coq phony
 	+@make -f Makefile.coq $@
@@ -25,7 +17,7 @@ clean: Makefile.coq
 
 # Create Coq Makefile. POSIX awk can't do in-place editing, but coq_makefile wants the real filename, so we do some file gymnastics.
 Makefile.coq: _CoqProject Makefile awk.Makefile
-	coq_makefile $(COQ_MAKEFILE_FLAGS) -f _CoqProject -o Makefile.coq
+	coq_makefile -f _CoqProject -o Makefile.coq
 	mv Makefile.coq Makefile.coq.tmp && awk -f awk.Makefile Makefile.coq.tmp > Makefile.coq && rm Makefile.coq.tmp
 
 # Install build-dependencies
diff --git a/_CoqProject b/_CoqProject
index 99afce68ce287ee66d07fdc33095f8a96fc2f4d4..dbeb27192793aeb041d3f2ebe60e9ae02431656b 100644
--- a/_CoqProject
+++ b/_CoqProject
@@ -1,4 +1,5 @@
 -Q theories iris
+-arg -w -arg -notation-overridden,-redundant-canonical-projection,-several-object-files
 theories/algebra/cmra.v
 theories/algebra/cmra_big_op.v
 theories/algebra/cmra_tactics.v
diff --git a/build/opam-pins.sh b/build/opam-pins.sh
index 669cd99b833df5259808f3b8f3fae1f96f466271..5291cb234701dbaba66e19717a4ef242fc9e83e8 100755
--- a/build/opam-pins.sh
+++ b/build/opam-pins.sh
@@ -4,18 +4,23 @@ set -e
 ## Usage:
 ##   ./opam-pins.sh < opam.pins
 
+if ! which curl >/dev/null; then
+    echo "opam-pins needs curl. Please install curl and try again."
+    exit 1
+fi
+
 # Process stdin
 while read PACKAGE URL HASH; do
     if echo "$URL" | egrep '^https://gitlab\.mpi-sws\.org' > /dev/null; then
         echo "[opam-pins] Recursing into $URL"
         # an MPI URL -- try doing recursive pin processing
-        curl -f "$URL/raw/$HASH" 2> /dev/null | "$0"
+        curl -f "$URL/raw/$HASH/opam.pins" 2>/dev/null | "$0"
     fi
     if opam pin list | fgrep "$PACKAGE.dev.$HASH " > /dev/null; then
         echo "[opam-pins] $PACKAGE already at commit $HASH"
     else
         echo "[opam-pins] Applying pin: $PACKAGE -> $URL#$HASH"
         opam pin add "$PACKAGE.dev.$HASH" "$URL#$HASH" -k git -y -n
+        echo
     fi
-    echo
 done
diff --git a/opam b/opam
index f3f2e979e0c4a182dcfcfc2838c33679122c317b..ea44830afe14223fca69264c3d71383126bd61e1 100644
--- a/opam
+++ b/opam
@@ -13,7 +13,7 @@ build: [
 install: [make "install"]
 remove: [ "sh" "-c" "rm -rf '%{lib}%/coq/user-contrib/iris'" ]
 depends: [
-  "coq" { ((>= "8.5.1" & < "8.7~") | (= "dev"))}
+  "coq" { ((>= "8.6" & < "8.7~") | (= "dev"))}
   "coq-mathcomp-ssreflect" { ((>= "1.6.1" & < "1.7~") | (= "dev"))}
   "coq-stdpp"
 ]