diff --git a/lib/CPUs/JCpu/ghdl/cpu_itest.make b/lib/CPUs/JCpu/ghdl/cpu_itest.make
index e7de19c..4810ae0 100644
--- a/lib/CPUs/JCpu/ghdl/cpu_itest.make
+++ b/lib/CPUs/JCpu/ghdl/cpu_itest.make
@@ -12,6 +12,7 @@ SRCS += ../src/tb_cpu_itest.vhd
 # Compile
 TARGET := cpu_itest
 ENTITY := tb_cpu
+WAVE_FORMAT := ghw
 
 include $(VHDL_HOME)/make/ghdl.mk
 
diff --git a/lib/CPUs/JCpu/ghdl/mul8x8.make b/lib/CPUs/JCpu/ghdl/mul8x8.make
index b211dd7..3513791 100644
--- a/lib/CPUs/JCpu/ghdl/mul8x8.make
+++ b/lib/CPUs/JCpu/ghdl/mul8x8.make
@@ -11,6 +11,7 @@ SRCS += ../src/tb_cpu_embedded.vhd
 # Compile
 TARGET := mul8x8
 ENTITY := tb_cpu_embedded
+WAVE_FORMAT := ghw
 
 include $(VHDL_HOME)/make/ghdl.mk
 
diff --git a/lib/CPUs/JCpu/ghdl/reti_issue.make b/lib/CPUs/JCpu/ghdl/reti_issue.make
index fb3d3c0..d1b869a 100644
--- a/lib/CPUs/JCpu/ghdl/reti_issue.make
+++ b/lib/CPUs/JCpu/ghdl/reti_issue.make
@@ -12,6 +12,7 @@ SRCS += ../src/tb_cpu_itest.vhd
 # Compile
 TARGET := reti_issue
 ENTITY := tb_cpu
+WAVE_FORMAT := ghw
 
 include $(VHDL_HOME)/make/ghdl.mk