diff --git a/Makefile b/Makefile
index 0f68e7b4be..905a60a3b6 100644
--- a/Makefile
+++ b/Makefile
@@ -245,14 +245,16 @@ tests:
 #
 .PHONY:	clean
 clean:
-	$(Q) $(RMDIR) $(BUILD_DIR)*.build > /dev/null
-	$(Q) $(REMOVE) $(IMAGE_DIR)*.px4 > /dev/null
+	@echo > /dev/null
+	$(Q) $(RMDIR) $(BUILD_DIR)*.build
+	$(Q) $(REMOVE) $(IMAGE_DIR)*.px4
 
 .PHONY:	distclean
 distclean: clean
-	$(Q) $(REMOVE) $(ARCHIVE_DIR)*.export > /dev/null
-	$(Q) $(MAKE) -C $(NUTTX_SRC) -r $(MQUIET) distclean > /dev/null
-	$(Q) (cd $(NUTTX_SRC)/configs && $(FIND) . -maxdepth 1 -type l -delete) > /dev/null
+	@echo > /dev/null
+	$(Q) $(REMOVE) $(ARCHIVE_DIR)*.export
+	$(Q) $(MAKE) -C $(NUTTX_SRC) -r $(MQUIET) distclean
+	$(Q) (cd $(NUTTX_SRC)/configs && $(FIND) . -maxdepth 1 -type l -delete)
 
 #
 # Print some help text
diff --git a/nuttx-configs/aerocore/nsh/Make.defs b/nuttx-configs/aerocore/nsh/Make.defs
index c7a1b71bbd..c1f5a8ac42 100644
--- a/nuttx-configs/aerocore/nsh/Make.defs
+++ b/nuttx-configs/aerocore/nsh/Make.defs
@@ -119,6 +119,7 @@ endif
 ARCHCFLAGS		 = -std=gnu99
 ARCHCXXFLAGS		 = -fno-exceptions -fno-rtti -std=gnu++0x
 ARCHWARNINGS		 = -Wall \
+			   -Wno-sign-compare \
 			   -Wextra \
 			   -Wdouble-promotion \
 			   -Wshadow \
diff --git a/nuttx-configs/px4fmu-v1/nsh/Make.defs b/nuttx-configs/px4fmu-v1/nsh/Make.defs
index f055cfddf8..5e28f2473d 100644
--- a/nuttx-configs/px4fmu-v1/nsh/Make.defs
+++ b/nuttx-configs/px4fmu-v1/nsh/Make.defs
@@ -119,6 +119,7 @@ endif
 ARCHCFLAGS		 = -std=gnu99
 ARCHCXXFLAGS		 = -fno-exceptions -fno-rtti -std=gnu++0x
 ARCHWARNINGS		 = -Wall \
+			   -Wno-sign-compare \
 			   -Wextra \
 			   -Wdouble-promotion \
 			   -Wshadow \
diff --git a/nuttx-configs/px4fmu-v2/nsh/Make.defs b/nuttx-configs/px4fmu-v2/nsh/Make.defs
index f660deeca7..99f3b3140d 100644
--- a/nuttx-configs/px4fmu-v2/nsh/Make.defs
+++ b/nuttx-configs/px4fmu-v2/nsh/Make.defs
@@ -119,6 +119,7 @@ endif
 ARCHCFLAGS		 = -std=gnu99
 ARCHCXXFLAGS		 = -fno-exceptions -fno-rtti -std=gnu++0x
 ARCHWARNINGS		 = -Wall \
+			   -Wno-sign-compare \
 			   -Wextra \
 			   -Wdouble-promotion \
 			   -Wshadow \
diff --git a/nuttx-configs/px4io-v1/nsh/Make.defs b/nuttx-configs/px4io-v1/nsh/Make.defs
index e96be6a1f2..b4f5577aed 100644
--- a/nuttx-configs/px4io-v1/nsh/Make.defs
+++ b/nuttx-configs/px4io-v1/nsh/Make.defs
@@ -108,6 +108,7 @@ endif
 ARCHCFLAGS		 = -std=gnu99
 ARCHCXXFLAGS		 = -fno-exceptions -fno-rtti -std=gnu++0x
 ARCHWARNINGS		 = -Wall \
+         -Wno-sign-compare \
 			   -Wextra \
 			   -Wdouble-promotion \
 			   -Wshadow \
diff --git a/nuttx-configs/px4io-v2/nsh/Make.defs b/nuttx-configs/px4io-v2/nsh/Make.defs
index 4a8df27388..51420eb23d 100644
--- a/nuttx-configs/px4io-v2/nsh/Make.defs
+++ b/nuttx-configs/px4io-v2/nsh/Make.defs
@@ -108,6 +108,7 @@ endif
 ARCHCFLAGS		 = -std=gnu99
 ARCHCXXFLAGS		 = -fno-exceptions -fno-rtti -std=gnu++0x
 ARCHWARNINGS		 = -Wall \
+         -Wno-sign-compare \
 			   -Wextra \
 			   -Wdouble-promotion \
 			   -Wshadow \