diff --git a/cpu/esp32/Makefile.include b/cpu/esp32/Makefile.include
index 0197450624..f3816578ea 100644
--- a/cpu/esp32/Makefile.include
+++ b/cpu/esp32/Makefile.include
@@ -109,6 +109,7 @@ CFLAGS  += -fdata-sections -ffunction-sections -fzero-initialized-in-bss
 
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-overflow
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-truncation
+OPTIONAL_CFLAGS_BLACKLIST += -gz
 
 ASFLAGS += --longcalls --text-section-literals
 
diff --git a/cpu/esp8266/Makefile.include b/cpu/esp8266/Makefile.include
index 7fbba01f7a..786e542fa3 100644
--- a/cpu/esp8266/Makefile.include
+++ b/cpu/esp8266/Makefile.include
@@ -165,3 +165,4 @@ endif
 OPTIONAL_CFLAGS_BLACKLIST += -fdiagnostics-color
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-overflow
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-truncation
+OPTIONAL_CFLAGS_BLACKLIST += -gz
diff --git a/makefiles/arch/atmega.inc.mk b/makefiles/arch/atmega.inc.mk
index 5789a00a1b..0ea8d8609c 100644
--- a/makefiles/arch/atmega.inc.mk
+++ b/makefiles/arch/atmega.inc.mk
@@ -53,3 +53,4 @@ endif
 
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-overflow
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-truncation
+OPTIONAL_CFLAGS_BLACKLIST += -gz
diff --git a/makefiles/arch/mips.inc.mk b/makefiles/arch/mips.inc.mk
index 27053bff0c..4d66af419a 100644
--- a/makefiles/arch/mips.inc.mk
+++ b/makefiles/arch/mips.inc.mk
@@ -69,3 +69,4 @@ export LINKFLAGS += -Wl,--gc-sections
 
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-overflow
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-truncation
+OPTIONAL_CFLAGS_BLACKLIST += -gz
diff --git a/makefiles/arch/msp430.inc.mk b/makefiles/arch/msp430.inc.mk
index 31b75020f9..bf3e1a6d0d 100644
--- a/makefiles/arch/msp430.inc.mk
+++ b/makefiles/arch/msp430.inc.mk
@@ -18,3 +18,4 @@ export LINKFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) -Wl,--gc-sections
 OPTIONAL_CFLAGS_BLACKLIST += -fdiagnostics-color
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-overflow
 OPTIONAL_CFLAGS_BLACKLIST += -Wformat-truncation
+OPTIONAL_CFLAGS_BLACKLIST += -gz
diff --git a/makefiles/cflags.inc.mk b/makefiles/cflags.inc.mk
index 96627d22f4..4f1b163963 100644
--- a/makefiles/cflags.inc.mk
+++ b/makefiles/cflags.inc.mk
@@ -38,6 +38,11 @@ endif
 # Forbid common symbols to prevent accidental aliasing.
 CFLAGS += -fno-common
 
+# Compress debug info. This saves approximately 50% of disk usage.
+# It has no effect if debugging information is not emitted, so it can be left
+# on unconditionally.
+OPTIONAL_CFLAGS += -gz
+
 # Enable all default warnings and all extra warnings
 CFLAGS += -Wall -Wextra
 # Enable additional checks for printf/scanf format strings