diff --git a/caddyconfig/httpcaddyfile/builtins.go b/caddyconfig/httpcaddyfile/builtins.go
index 311a29e02..da231fbd9 100644
--- a/caddyconfig/httpcaddyfile/builtins.go
+++ b/caddyconfig/httpcaddyfile/builtins.go
@@ -1053,7 +1053,7 @@ func parseLogHelper(h Helper, globalLogNames map[string]struct{}) ([]ConfigValue
 					if !d.NextArg() {
 						return nil, d.ArgErr()
 					}
-					interval, err := time.ParseDuration(d.Val() + "ns")
+					interval, err := caddy.ParseDuration(d.Val())
 					if err != nil {
 						return nil, d.Errf("failed to parse interval: %v", err)
 					}
diff --git a/caddyconfig/httpcaddyfile/builtins_test.go b/caddyconfig/httpcaddyfile/builtins_test.go
index c23531f22..9cff29039 100644
--- a/caddyconfig/httpcaddyfile/builtins_test.go
+++ b/caddyconfig/httpcaddyfile/builtins_test.go
@@ -66,14 +66,14 @@ func TestLogDirectiveSyntax(t *testing.T) {
 			input: `:8080 {
 				log {
 					sampling {
-						interval 2
+						interval 2s
 						first 3
 						thereafter 4
 					}
 				}
 			}
 			`,
-			output:      `{"logging":{"logs":{"default":{"exclude":["http.log.access.log0"]},"log0":{"sampling":{"interval":2,"first":3,"thereafter":4},"include":["http.log.access.log0"]}}},"apps":{"http":{"servers":{"srv0":{"listen":[":8080"],"logs":{"default_logger_name":"log0"}}}}}}`,
+			output:      `{"logging":{"logs":{"default":{"exclude":["http.log.access.log0"]},"log0":{"sampling":{"interval":2000000000,"first":3,"thereafter":4},"include":["http.log.access.log0"]}}},"apps":{"http":{"servers":{"srv0":{"listen":[":8080"],"logs":{"default_logger_name":"log0"}}}}}}`,
 			expectError: false,
 		},
 	} {
diff --git a/caddytest/integration/caddyfile_adapt/global_options_log_sampling.caddyfiletest b/caddytest/integration/caddyfile_adapt/global_options_log_sampling.caddyfiletest
index 12b73b2b7..caa755a02 100644
--- a/caddytest/integration/caddyfile_adapt/global_options_log_sampling.caddyfiletest
+++ b/caddytest/integration/caddyfile_adapt/global_options_log_sampling.caddyfiletest
@@ -1,7 +1,7 @@
 {
 	log {
 		sampling {
-			interval 300
+			interval 5m
 			first 50
 			thereafter 40
 		}
@@ -13,7 +13,7 @@
 		"logs": {
 			"default": {
 				"sampling": {
-					"interval": 300,
+					"interval": 300000000000,
 					"first": 50,
 					"thereafter": 40
 				}
diff --git a/caddytest/integration/caddyfile_adapt/log_sampling.caddyfiletest b/caddytest/integration/caddyfile_adapt/log_sampling.caddyfiletest
index b58622572..fcda093a6 100644
--- a/caddytest/integration/caddyfile_adapt/log_sampling.caddyfiletest
+++ b/caddytest/integration/caddyfile_adapt/log_sampling.caddyfiletest
@@ -1,7 +1,7 @@
 :80 {
 	log {
 		sampling {
-			interval 300
+			interval 5m
 			first 50
 			thereafter 40
 		}
@@ -18,7 +18,7 @@
 			},
 			"log0": {
 				"sampling": {
-					"interval": 300,
+					"interval": 300000000000,
 					"first": 50,
 					"thereafter": 40
 				},