diff --git a/ahrs/common/quaternion.py b/ahrs/common/quaternion.py
index 6806723..9edf5bb 100644
--- a/ahrs/common/quaternion.py
+++ b/ahrs/common/quaternion.py
@@ -3011,6 +3011,10 @@ def slerp_nan(self, inplace: bool = True) -> np.ndarray:
         self.remove_jumps()
         interpolated_quaternions = np.copy(self.array)
         nan_intervals = get_nan_intervals(self.array)
+        if len(nan_intervals) == 0:
+            if inplace:
+                return None
+            return interpolated_quaternions
         for interval in nan_intervals:
             interpolated_quaternions[interval[0]:interval[1]+1] = slerp(
                 self.array[interval[0]-1],
diff --git a/ahrs/utils/core.py b/ahrs/utils/core.py
index 2931a60..0fb2060 100644
--- a/ahrs/utils/core.py
+++ b/ahrs/utils/core.py
@@ -67,4 +67,6 @@ def get_nan_intervals(data: np.ndarray) -> list:
     isnan_list = np.any(np.isnan(data), axis=1) if data.ndim > 1 else np.isnan(data)
     nan_indices = np.where(isnan_list == True)[0]
     intervals = np.split(nan_indices, np.where(np.diff(nan_indices) > 1)[0] + 1)
+    if len(intervals) == 0:
+        return []
     return [(interval[0], interval[-1]) for interval in intervals]