diff --git a/src/cmd/go/internal/load/flag.go b/src/cmd/go/internal/load/flag.go
index 440cb86134..274c0f23e2 100644
--- a/src/cmd/go/internal/load/flag.go
+++ b/src/cmd/go/internal/load/flag.go
@@ -22,8 +22,9 @@ var (
 // that allows specifying different effective flags for different packages.
 // See 'go help build' for more details about per-package flags.
 type PerPackageFlag struct {
-	present bool
-	values  []ppfValue
+	present      bool
+	values       []ppfValue
+	seenPackages map[*Package]bool // the packages for which the flags have already been set
 }
 
 // A ppfValue is a single <pattern>=<flags> per-package flag value.
diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go
index 193a27a713..9d7d32b5d1 100644
--- a/src/cmd/go/internal/load/pkg.go
+++ b/src/cmd/go/internal/load/pkg.go
@@ -210,7 +210,6 @@ type PackageInternal struct {
 	BuildInfo         string               // add this info to package main
 	TestmainGo        *[]byte              // content for _testmain.go
 	Embed             map[string][]string  // //go:embed comment mapping
-	FlagsSet          bool                 // whether the flags have been set
 	OrigImportPath    string               // original import path before adding '_test' suffix
 
 	Asmflags   []string // -asmflags for this package
@@ -2628,18 +2627,20 @@ func (e *mainPackageError) ImportPath() string {
 
 func setToolFlags(pkgs ...*Package) {
 	for _, p := range PackageList(pkgs) {
-		// TODO(jayconrod,katiehockman): See if there's a better way to do this.
-		if p.Internal.FlagsSet {
-			// The flags have already been set, so don't re-run this and
-			// potentially clear existing flags.
-			continue
-		} else {
-			p.Internal.FlagsSet = true
+		appendFlags(p, &p.Internal.Asmflags, &BuildAsmflags)
+		appendFlags(p, &p.Internal.Gcflags, &BuildGcflags)
+		appendFlags(p, &p.Internal.Ldflags, &BuildLdflags)
+		appendFlags(p, &p.Internal.Gccgoflags, &BuildGccgoflags)
+	}
+}
+
+func appendFlags(p *Package, flags *[]string, packageFlag *PerPackageFlag) {
+	if !packageFlag.seenPackages[p] {
+		if packageFlag.seenPackages == nil {
+			packageFlag.seenPackages = make(map[*Package]bool)
 		}
-		p.Internal.Asmflags = BuildAsmflags.For(p)
-		p.Internal.Gcflags = BuildGcflags.For(p)
-		p.Internal.Ldflags = BuildLdflags.For(p)
-		p.Internal.Gccgoflags = BuildGccgoflags.For(p)
+		packageFlag.seenPackages[p] = true
+		*flags = append(*flags, packageFlag.For(p)...)
 	}
 }
 
diff --git a/src/cmd/go/internal/test/test.go b/src/cmd/go/internal/test/test.go
index d5afae782b..012a75123b 100644
--- a/src/cmd/go/internal/test/test.go
+++ b/src/cmd/go/internal/test/test.go
@@ -826,11 +826,21 @@ func runTest(ctx context.Context, cmd *base.Command, args []string) {
 		}
 	}
 
+	// Inform the compiler that it should instrument the binary at
+	// build-time when fuzzing is enabled.
 	fuzzFlags := work.FuzzInstrumentFlags()
 	if testFuzz != "" && fuzzFlags != nil {
-		// Inform the compiler that it should instrument the binary at
-		// build-time when fuzzing is enabled.
-		for _, p := range load.PackageList(pkgs) {
+		// Don't instrument packages which may affect coverage guidance but are
+		// unlikely to be useful.
+		var fuzzNoInstrument = map[string]bool{
+			"testing":       true,
+			"internal/fuzz": true,
+			"runtime":       true,
+		}
+		for _, p := range load.TestPackageList(ctx, pkgOpts, pkgs) {
+			if fuzzNoInstrument[p.ImportPath] {
+				continue
+			}
 			p.Internal.Gcflags = append(p.Internal.Gcflags, fuzzFlags...)
 		}
 	}