diff --git a/Makefile b/Makefile
index 5ba89be81721bd8141d2882a084de8a11aafcdae..413374c614a995c097caba9f1beb10499e870a2e 100644
--- a/Makefile
+++ b/Makefile
@@ -157,7 +157,7 @@ LD_asan = clang
 LDXX_asan = clang++
 CPPFLAGS_asan = -O0 -fsanitize=address -fno-omit-frame-pointer
 LDFLAGS_asan = -fsanitize=address
-DEFINES_asan = GRPC_TEST_SLOWDOWN_BUILD_FACTOR=5
+DEFINES_asan = GRPC_TEST_SLOWDOWN_BUILD_FACTOR=3
 
 VALID_CONFIG_msan = 1
 REQUIRE_CUSTOM_LIBRARIES_msan = 1
@@ -168,7 +168,7 @@ LDXX_msan = clang++-libc++
 CPPFLAGS_msan = -O0 -fsanitize=memory -fsanitize-memory-track-origins -fno-omit-frame-pointer -DGTEST_HAS_TR1_TUPLE=0 -DGTEST_USE_OWN_TR1_TUPLE=1
 OPENSSL_CFLAGS_msan = -DPURIFY
 LDFLAGS_msan = -fsanitize=memory -DGTEST_HAS_TR1_TUPLE=0 -DGTEST_USE_OWN_TR1_TUPLE=1
-DEFINES_msan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=20
+DEFINES_msan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=4
 
 VALID_CONFIG_ubsan = 1
 REQUIRE_CUSTOM_LIBRARIES_ubsan = 1
@@ -179,7 +179,7 @@ LDXX_ubsan = clang++
 CPPFLAGS_ubsan = -O1 -fsanitize=undefined -fno-omit-frame-pointer
 OPENSSL_CFLAGS_ubsan = -DPURIFY
 LDFLAGS_ubsan = -fsanitize=undefined
-DEFINES_ubsan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=10
+DEFINES_ubsan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=3
 
 VALID_CONFIG_gcov = 1
 CC_gcov = gcc
diff --git a/templates/Makefile.template b/templates/Makefile.template
index 3b04d7d04152e1ae9cb7438b977bf8e9a67cb3b9..2ebb7c3d0ae109e71e57c1ce33fccf984438d556 100644
--- a/templates/Makefile.template
+++ b/templates/Makefile.template
@@ -171,7 +171,7 @@ LD_asan = clang
 LDXX_asan = clang++
 CPPFLAGS_asan = -O0 -fsanitize=address -fno-omit-frame-pointer
 LDFLAGS_asan = -fsanitize=address
-DEFINES_asan = GRPC_TEST_SLOWDOWN_BUILD_FACTOR=5
+DEFINES_asan = GRPC_TEST_SLOWDOWN_BUILD_FACTOR=3
 
 VALID_CONFIG_msan = 1
 REQUIRE_CUSTOM_LIBRARIES_msan = 1
@@ -182,7 +182,7 @@ LDXX_msan = clang++-libc++
 CPPFLAGS_msan = -O0 -fsanitize=memory -fsanitize-memory-track-origins -fno-omit-frame-pointer -DGTEST_HAS_TR1_TUPLE=0 -DGTEST_USE_OWN_TR1_TUPLE=1
 OPENSSL_CFLAGS_msan = -DPURIFY
 LDFLAGS_msan = -fsanitize=memory -DGTEST_HAS_TR1_TUPLE=0 -DGTEST_USE_OWN_TR1_TUPLE=1
-DEFINES_msan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=20
+DEFINES_msan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=4
 
 VALID_CONFIG_ubsan = 1
 REQUIRE_CUSTOM_LIBRARIES_ubsan = 1
@@ -193,7 +193,7 @@ LDXX_ubsan = clang++
 CPPFLAGS_ubsan = -O1 -fsanitize=undefined -fno-omit-frame-pointer
 OPENSSL_CFLAGS_ubsan = -DPURIFY
 LDFLAGS_ubsan = -fsanitize=undefined
-DEFINES_ubsan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=10
+DEFINES_ubsan = NDEBUG GRPC_TEST_SLOWDOWN_BUILD_FACTOR=3
 
 VALID_CONFIG_gcov = 1
 CC_gcov = gcc