diff --git a/datastores/mysql.go b/datastores/mysql.go
index d3e3921..e556f22 100644
--- a/datastores/mysql.go
+++ b/datastores/mysql.go
@@ -110,7 +110,7 @@ func (ds Mysql) FindProfileByKeycloakID(keycloakId string) (*proto.Profile, erro
 
 	profiles, err := ds.processProfiles([]milpacs.Profile{profile})
 	if err != nil {
-		return nil, fmt.Errorf("error generating profile")
+		return nil, fmt.Errorf("error generating profile: %w", err)
 	}
 
 	return profiles[profile.RelationId], nil
@@ -134,7 +134,7 @@ func (ds Mysql) FindProfileByDiscordID(discordId string) (*proto.Profile, error)
 
 	profiles, err := ds.processProfiles([]milpacs.Profile{profile})
 	if err != nil {
-		return nil, fmt.Errorf("error generating profile")
+		return nil, fmt.Errorf("error generating profile: %w", err)
 	}
 
 	return profiles[profile.RelationId], nil
@@ -356,7 +356,7 @@ func (ds Mysql) FindS1UniformsRosterByType(rosterType proto.RosterType) (*proto.
 		milpac, err := ds.generateS1UniformsProtoProfile(profile)
 
 		if err != nil {
-			return nil, fmt.Errorf("error generating profile")
+			return nil, fmt.Errorf("error generating profile: %w", err)
 		}
 		profiles[profile.RelationId] = milpac
 	}
diff --git a/servers/grpc/grpc.go b/servers/grpc/grpc.go
index fd59b10..4b9f6f0 100644
--- a/servers/grpc/grpc.go
+++ b/servers/grpc/grpc.go
@@ -80,7 +80,7 @@ func (server *MilpacsService) GetRoster(ctx context.Context, request *proto.Rost
 		return nil, err
 	}
 	if request.Roster == proto.RosterType_ROSTER_TYPE_UNSPECIFIED {
-		return nil, errors.New("cannot request null roster type")
+		return nil, status.Errorf(codes.InvalidArgument, "cannot request null roster type")
 	}
 
 	roster, err := server.Datastore.FindRosterByType(request.Roster)
@@ -98,7 +98,7 @@ func (server *MilpacsService) GetUserViaKeycloakId(ctx context.Context, request
 	}
 
 	if request.GetKeycloakId() == "" {
-		Warn.Println("Empty Keycloak ID provided, cannot return profile")
+		return nil, status.Errorf(codes.InvalidArgument, "keycloak id cannot be empty")
 	}
 
 	profile, err := server.Datastore.FindProfileByKeycloakID(request.GetKeycloakId())
@@ -119,7 +119,7 @@ func (server *MilpacsService) GetUserViaDiscordId(ctx context.Context, request *
 	}
 
 	if request.GetDiscordId() == "" {
-		Warn.Println("Empty Discord ID provided, cannot return profile")
+		return nil, status.Errorf(codes.InvalidArgument, "discord id cannot be empty")
 	}
 
 	profile, err := server.Datastore.FindProfileByDiscordID(request.GetDiscordId())
@@ -138,7 +138,7 @@ func (server *MilpacsService) GetLiteRoster(ctx context.Context, request *proto.
 		return nil, err
 	}
 	if request.Roster == proto.RosterType_ROSTER_TYPE_UNSPECIFIED {
-		return nil, errors.New("cannot request null roster type")
+		return nil, status.Errorf(codes.InvalidArgument, "cannot request null roster type")
 	}
 
 	roster, err := server.Datastore.FindLiteRosterByType(request.Roster)
@@ -170,7 +170,7 @@ func (server *MilpacsService) GetS1UniformsRoster(ctx context.Context, request *
 		return nil, err
 	}
 	if request.Roster == proto.RosterType_ROSTER_TYPE_UNSPECIFIED {
-		return nil, errors.New("cannot request null roster type")
+		return nil, status.Errorf(codes.InvalidArgument, "cannot request null roster type")
 	}
 
 	roster, err := server.Datastore.FindS1UniformsRosterByType(request.Roster)
diff --git a/servers/grpc/milpacs_test.go b/servers/grpc/milpacs_test.go
index 2f64718..6c1c489 100644
--- a/servers/grpc/milpacs_test.go
+++ b/servers/grpc/milpacs_test.go
@@ -142,6 +142,62 @@ func TestGetGamertagProfile_DatastoreError(t *testing.T) {
 	assert.Equal(t, codes.Internal, st.Code())
 }
 
+func TestGetUserViaKeycloakId_EmptyID_InvalidArgument(t *testing.T) {
+	// findProfileByKeycloakID left unset: a fall-through to the datastore
+	// nil-derefs and panics, proving the handler early-returns instead.
+	svc := &MilpacsService{Datastore: &fakeDatastore{}}
+	_, err := svc.GetUserViaKeycloakId(withMilpacsKey("read"), &proto.KeycloakIdRequest{KeycloakId: ""})
+	require.Error(t, err)
+	st, ok := status.FromError(err)
+	require.True(t, ok)
+	assert.Equal(t, codes.InvalidArgument, st.Code())
+}
+
+func TestGetUserViaDiscordId_EmptyID_InvalidArgument(t *testing.T) {
+	svc := &MilpacsService{Datastore: &fakeDatastore{}}
+	_, err := svc.GetUserViaDiscordId(withMilpacsKey("read"), &proto.DiscordIdRequest{DiscordId: ""})
+	require.Error(t, err)
+	st, ok := status.FromError(err)
+	require.True(t, ok)
+	assert.Equal(t, codes.InvalidArgument, st.Code())
+}
+
+func TestGetGamertagProfile_Empty_InvalidArgument(t *testing.T) {
+	svc := &MilpacsService{Datastore: &fakeDatastore{}}
+	_, err := svc.GetGamertagProfile(withMilpacsKey("read"), &proto.GamertagRequest{Gamertag: ""})
+	require.Error(t, err)
+	st, ok := status.FromError(err)
+	require.True(t, ok)
+	assert.Equal(t, codes.InvalidArgument, st.Code())
+}
+
+func TestGetRoster_NullType_InvalidArgument(t *testing.T) {
+	svc := &MilpacsService{Datastore: &fakeDatastore{}}
+	_, err := svc.GetRoster(withMilpacsKey("read"), &proto.RosterRequest{Roster: proto.RosterType_ROSTER_TYPE_UNSPECIFIED})
+	require.Error(t, err)
+	st, ok := status.FromError(err)
+	require.True(t, ok)
+	assert.Equal(t, codes.InvalidArgument, st.Code())
+}
+
+func TestGetLiteRoster_NullType_InvalidArgument(t *testing.T) {
+	svc := &MilpacsService{Datastore: &fakeDatastore{}}
+	_, err := svc.GetLiteRoster(withMilpacsKey("read"), &proto.RosterRequest{Roster: proto.RosterType_ROSTER_TYPE_UNSPECIFIED})
+	require.Error(t, err)
+	st, ok := status.FromError(err)
+	require.True(t, ok)
+	assert.Equal(t, codes.InvalidArgument, st.Code())
+}
+
+func TestGetS1UniformsRoster_NullType_InvalidArgument(t *testing.T) {
+	svc := &MilpacsService{Datastore: &fakeDatastore{}}
+	_, err := svc.GetS1UniformsRoster(withMilpacsKey("read"), &proto.RosterRequest{Roster: proto.RosterType_ROSTER_TYPE_UNSPECIFIED})
+	require.Error(t, err)
+	st, ok := status.FromError(err)
+	require.True(t, ok)
+	assert.Equal(t, codes.InvalidArgument, st.Code())
+}
+
 func TestGetRoster_DatastoreError(t *testing.T) {
 	svc := &MilpacsService{Datastore: &fakeDatastore{
 		findRosterByType: func(proto.RosterType) (*proto.Roster, error) {