diff --git a/implementations/micrometer-registry-otlp/src/main/java/io/micrometer/registry/otlp/OtlpMeterRegistry.java b/implementations/micrometer-registry-otlp/src/main/java/io/micrometer/registry/otlp/OtlpMeterRegistry.java
index 3be079089..fe66b92bd 100644
--- a/implementations/micrometer-registry-otlp/src/main/java/io/micrometer/registry/otlp/OtlpMeterRegistry.java
+++ b/implementations/micrometer-registry-otlp/src/main/java/io/micrometer/registry/otlp/OtlpMeterRegistry.java
@@ -89,7 +89,7 @@ public class OtlpMeterRegistry extends PushMeterRegistry {
 
     // Time when the last scheduled rollOver has started. Applicable only for delta
     // flavour.
-    private long lastMeterRolloverStartTime = -1;
+    private volatile long lastMeterRolloverStartTime = -1;
 
     @Nullable
     private ScheduledExecutorService meterPollingService;
diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/step/StepMeterRegistry.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/step/StepMeterRegistry.java
index b9dfbfe77..39642986b 100644
--- a/micrometer-core/src/main/java/io/micrometer/core/instrument/step/StepMeterRegistry.java
+++ b/micrometer-core/src/main/java/io/micrometer/core/instrument/step/StepMeterRegistry.java
@@ -51,7 +51,7 @@ public abstract class StepMeterRegistry extends PushMeterRegistry {
     private ScheduledExecutorService meterPollingService;
 
     // Time when the last scheduled rollOver has started.
-    private long lastMeterRolloverStartTime = -1;
+    private volatile long lastMeterRolloverStartTime = -1;
 
     public StepMeterRegistry(StepRegistryConfig config, Clock clock) {
         super(config, clock);