diff --git a/src/AdvancedADC.cpp b/src/AdvancedADC.cpp
index 9078be4..e01c894 100644
--- a/src/AdvancedADC.cpp
+++ b/src/AdvancedADC.cpp
@@ -117,7 +117,7 @@ int AdvancedADC::begin(uint32_t resolution, uint32_t sample_rate, size_t n_sampl
     ADCName instance = ADC_NP;
 
     // Sanity checks.
-    if (resolution >= AN_ARRAY_SIZE(ADC_RES_LUT)) {
+    if (resolution >= AN_ARRAY_SIZE(ADC_RES_LUT) || (descr && descr->pool)) {
         return 0;
     }
 
diff --git a/src/AdvancedDAC.cpp b/src/AdvancedDAC.cpp
index fc04461..443336f 100644
--- a/src/AdvancedDAC.cpp
+++ b/src/AdvancedDAC.cpp
@@ -135,7 +135,7 @@ void AdvancedDAC::write(DMABuffer<Sample> &dmabuf) {
 
 int AdvancedDAC::begin(uint32_t resolution, uint32_t frequency, size_t n_samples, size_t n_buffers) {
     // Sanity checks.
-    if (resolution >= AN_ARRAY_SIZE(DAC_RES_LUT)) {
+    if (resolution >= AN_ARRAY_SIZE(DAC_RES_LUT) || (descr && descr->pool)) {
         return 0;
     }