diff --git a/.circleci/run.sh b/.circleci/run.sh
index da7b7f8bf6..abfcfaa3af 100755
--- a/.circleci/run.sh
+++ b/.circleci/run.sh
@@ -90,7 +90,15 @@ setup_repos() {
 }
 
 style() {
-    make -f posix.mak style
+    source "$(CURL_USER_AGENT=\"$CURL_USER_AGENT\" bash ~/dlang/install.sh dmd-$HOST_DMD_VER --activate)"
+
+    # checkout a specific version of https://github.com/dlang/tools
+    if [ ! -d ../tools ] ; then
+        clone https://github.com/dlang/tools.git ../tools master
+    fi
+    git -C ../tools checkout 6ad91215253b52e6ecfc39fe1854815867c66f23
+
+    make -f posix.mak -j$N style MODEL="$MODEL"
 }
 
 coverage() {
@@ -114,7 +122,7 @@ codecov()
 case $1 in
     install-deps) install_deps ;;
     setup-repos) setup_repos ;;
-    style) style ;;
+    style) style;;
     coverage) coverage ;;
     codecov) codecov ;;
 esac
diff --git a/posix.mak b/posix.mak
index 901c810a35..42d3bb4ffe 100644
--- a/posix.mak
+++ b/posix.mak
@@ -6,6 +6,8 @@
 QUIET:=
 
 DMD_DIR=../dmd
+TOOLS_DIR=../tools
+DUB=dub
 
 include $(DMD_DIR)/src/osmodel.mak
 
@@ -90,7 +92,7 @@ endif
 PHOBOS_PATH=../phobos
 SHARED=$(if $(findstring $(OS),linux freebsd),1,)
 ROOT_DIR := $(shell pwd)
-PHOBOS_DFLAGS=-conf= $(MODEL_FLAG) -I$(ROOT_DIR)/import -I$(PHOBOS_PATH) -L-L$(PHOBOS_PATH)/generated/$(OS)/$(BUILD)/$(MODEL) $(PIC)
+PHOBOS_DFLAGS=-conf= $(MODEL_FLAG) -I$(ROOT_DIR)/import -I$(PHOBOS_PATH) -L-L$(PHOBOS_PATH)/generated/$(OS)/$(BUILD)/$(MODEL) $(PIC) -defaultlib= -debuglib=
 ifeq (1,$(SHARED))
 PHOBOS_DFLAGS+=-defaultlib=libphobos2.so -L-rpath=$(PHOBOS_PATH)/generated/$(OS)/$(BUILD)/$(MODEL)
 endif
@@ -362,12 +364,35 @@ test/%/.clean: test/%/Makefile
 # Submission to Druntime are required to conform to the DStyle
 # The tests below automate some, but not all parts of the DStyle guidelines.
 # See: http://dlang.org/dstyle.html
-style: checkwhitespace style_lint
+style: style_lint publictests
 
 style_lint:
 	@echo "Check for trailing whitespace"
 	$(GREP) -nr '[[:blank:]]$$' $(MANIFEST) ; test $$? -eq 1
 
+################################################################################
+# Check for missing imports in public unittest examples.
+################################################################################
+TESTS_EXTRACTOR=$(ROOT)/tests_extractor
+PUBLICTESTS_DIR=$(ROOT)/publictests
+
+publictests: $(addsuffix .publictests, $(basename $(SRCS)))
+
+$(TESTS_EXTRACTOR): $(TOOLS_DIR)/tests_extractor.d | $(LIB)
+	DFLAGS="$(PHOBOS_DFLAGS)" $(DUB) build --force --compiler=$${PWD}/$(DMD) --single $<
+	mv $(TOOLS_DIR)/tests_extractor $@
+
+################################################################################
+# Extract public tests of a module and test them in an separate file (i.e. without its module)
+# This is done to check for potentially missing imports in the examples, e.g.
+# make -f posix.mak std/format.publictests
+################################################################################
+%.publictests: %.d $(TESTS_EXTRACTOR) #| $(PUBLICTESTS_DIR)/.directory
+	@$(TESTS_EXTRACTOR) --inputdir  $< --outputdir $(PUBLICTESTS_DIR)
+	@$(DMD) $(PHOBOS_DFLAGS) -main $(UDFLAGS) -run $(PUBLICTESTS_DIR)/$(subst /,_,$<)
+
+################################################################################
+
 .PHONY : auto-tester-build
 auto-tester-build: target checkwhitespace
 
diff --git a/src/core/memory.d b/src/core/memory.d
index 43403f4adf..3e2ef721ce 100644
--- a/src/core/memory.d
+++ b/src/core/memory.d
@@ -1138,7 +1138,6 @@ unittest
 // Deleting raw memory
 unittest
 {
-    import core.memory : GC;
     auto a = GC.malloc(5);
     assert(GC.addrOf(cast(void*) a) != null);
     __delete(a);
diff --git a/src/object.d b/src/object.d
index babda211d8..0da53ba73f 100644
--- a/src/object.d
+++ b/src/object.d
@@ -2168,12 +2168,12 @@ auto byKeyValue(T : V[K], K, V)(T aa) pure nothrow @nogc @safe
                 {
                     auto p = (() @trusted => cast(substInout!K*) keyp) ();
                     return *p;
-                };
+                }
                 @property ref value() inout
                 {
                     auto p = (() @trusted => cast(substInout!V*) valp) ();
                     return *p;
-                };
+                }
             }
             return Pair(_aaRangeFrontKey(r),
                         _aaRangeFrontValue(r));