diff --git a/go.mod b/go.mod
index cc83da1f0..5f2e1a0f6 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,6 @@ require (
 	github.com/go-openapi/validate v0.19.7
 	github.com/golangci/golangci-lint v1.24.0
 	github.com/google/go-cmp v0.4.0
-	github.com/hansboder/gocovmerge v0.0.0-20190813150856-3552c2006da5
 	github.com/hansrodtang/randomcolor v0.0.0-20160512071917-d27108b3d7a5
 	github.com/jarcoal/httpmock v1.0.5
 	github.com/knadh/koanf v0.9.1
diff --git a/go.sum b/go.sum
index 322f45631..b00680b36 100644
--- a/go.sum
+++ b/go.sum
@@ -263,8 +263,6 @@ github.com/gostaticanalysis/analysisutil v0.0.0-20190318220348-4088753ea4d3/go.m
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
-github.com/hansboder/gocovmerge v0.0.0-20190813150856-3552c2006da5 h1:PKFOvrFdBuYn8F0GD0itonb8M/DFiSrDYfF54DUIE3M=
-github.com/hansboder/gocovmerge v0.0.0-20190813150856-3552c2006da5/go.mod h1:YuynvyiaysiM6eitHFN8mL+lRHEbZFTHG+hVXX1xZf8=
 github.com/hansrodtang/randomcolor v0.0.0-20160512071917-d27108b3d7a5 h1:9WT/rQ2tZI0TBZhBsA/dYU1bdI2QKaUzQ3X6YDwaLUY=
 github.com/hansrodtang/randomcolor v0.0.0-20160512071917-d27108b3d7a5/go.mod h1:XvzgNvkcPBKMxeywFlPioejZ5ulXi/GMLZDoBw915FA=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
diff --git a/make/go.mk b/make/go.mk
index 4013a83d4..e654ad601 100644
--- a/make/go.mk
+++ b/make/go.mk
@@ -21,10 +21,8 @@ cmd/karma/bindata_assetfs.go: $(GOBIN)/go-bindata-assetfs $(SOURCES_JS) ui/build
 $(NAME): go.mod go.sum cmd/karma/bindata_assetfs.go $(SOURCES_GO)
 	$(GO) build -ldflags "-X main.version=$(VERSION)" ./cmd/karma
 
-$(GOBIN)/gocovmerge: go.mod go.sum
-	$(GO) install github.com/hansboder/gocovmerge
 .PHONY: test-go
-test-go: $(GOBIN)/gocovmerge
+test-go:
 	@rm -f profile.*
 	$(ENV) ./scripts/test-unit.sh
 	$(ENV) ./scripts/test-main.sh
diff --git a/scripts/gocovmerge.sh b/scripts/gocovmerge.sh
index 6789adb9e..ded009fec 100755
--- a/scripts/gocovmerge.sh
+++ b/scripts/gocovmerge.sh
@@ -3,7 +3,12 @@
 set -o errexit
 set -o pipefail
 
-gocovmerge profile.* | grep -vE '^github.com/prymitive/karma/cmd/karma/bindata_assetfs.go:' > coverage.txt
+echo "mode: set" > coverage.txt
+cat profile.* \
+  | grep -v mode: \
+  | grep -vE '^github.com/prymitive/karma/cmd/karma/bindata_assetfs.go:' \
+  | sort -r \
+  | awk '{if($1 != last) {print $0;last=$1}}' >> coverage.txt
 rm -f profile.*
 
 go tool cover -func coverage.txt | tail -n 1 | awk '{print $3}'
diff --git a/tools.go b/tools.go
index 90ef30c33..cb6ac3bec 100644
--- a/tools.go
+++ b/tools.go
@@ -10,5 +10,4 @@ import (
 	_ "github.com/elazarl/go-bindata-assetfs"
 	_ "github.com/go-bindata/go-bindata/v3"
 	_ "github.com/golangci/golangci-lint/pkg/commands"
-	_ "github.com/hansboder/gocovmerge"
 )