diff --git a/boards/bluepill/Makefile.include b/boards/bluepill/Makefile.include
index c0b88cab9778cf39aa9460b4dfec033264701d99..353208a59bd8d1cae02f263d5b3774468a94cb6a 100644
--- a/boards/bluepill/Makefile.include
+++ b/boards/bluepill/Makefile.include
@@ -21,6 +21,7 @@ ifeq ($(PROGRAMMER),dfu-util)
   export RESET = # dfu-util has no support for resetting the device
 
   export OFLAGS = -O binary
+  HEXFILE = $(ELFFILE:.elf=.bin)
   export FFLAGS = -d 1d50:6017 -s 0x08002000:leave -D "$(HEXFILE)"
 else
 
diff --git a/boards/f4vi1/Makefile.include b/boards/f4vi1/Makefile.include
index dfaf742cacd6c7ad89b267528fcafedd503afa30..3ccea4ee55f57bb552206bed14c31aae1ee99a7c 100644
--- a/boards/f4vi1/Makefile.include
+++ b/boards/f4vi1/Makefile.include
@@ -16,5 +16,6 @@ export DEBUGSERVER = st-util
 
 # define st-flash parameters
 export OFLAGS = -O binary
+HEXFILE = $(ELFFILE:.elf=.bin)
 export FFLAGS = write $(HEXFILE) 0x8000000
 export DEBUGGER_FLAGS = $(RIOTBOARD)/$(BOARD)/dist/gdb.conf $(ELFFILE)
diff --git a/boards/nz32-sc151/Makefile.include b/boards/nz32-sc151/Makefile.include
index 0f50be0539386f1ad23096ef52da0a450a3045e2..ed4ef10e87056f3eb62d730a861fd357033951ce 100644
--- a/boards/nz32-sc151/Makefile.include
+++ b/boards/nz32-sc151/Makefile.include
@@ -14,6 +14,7 @@ export DEBUGGER = # dfu-util has no debugger
 export RESET = # dfu-util has no support for resetting the device
 
 export OFLAGS = -O binary
+HEXFILE = $(ELFFILE:.elf=.bin)
 export FFLAGS = -d $(ID) -a 0 -s 0x08000000:leave -D "$(HEXFILE)"
 export TERMFLAGS = -p $(PORT)
 
diff --git a/boards/spark-core/Makefile.include b/boards/spark-core/Makefile.include
index 223683097a654745d8363fa307e35bac4faf2acd..c264a630af9b8d7a2346d301e11ca1ed05b46a38 100644
--- a/boards/spark-core/Makefile.include
+++ b/boards/spark-core/Makefile.include
@@ -12,6 +12,7 @@ export DEBUGGER = # spark core has no debugger
 export RESET = # dfu-util has no support for resetting the device
 
 export OFLAGS = -O binary
+HEXFILE = $(ELFFILE:.elf=.bin)
 export FFLAGS = -d 1d50:607f -a 0 -s 0x08005000:leave -D "$(HEXFILE)"
 
 export INCLUDES += -I$(RIOTCPU)/$(CPU)/include/ -I$(RIOTBOARD)/$(BOARD)/include/