diff --git a/include/lsst/afw/detection/Psf.h b/include/lsst/afw/detection/Psf.h
index e5b5a6179..6e1dd25be 100644
--- a/include/lsst/afw/detection/Psf.h
+++ b/include/lsst/afw/detection/Psf.h
@@ -28,6 +28,7 @@
 
 #include <memory>
 
+#include "lsst/pex/exceptions.h"
 #include "lsst/utils/CacheFwd.h"
 #include "lsst/afw/geom/ellipses/Quadrupole.h"
 #include "lsst/afw/math/Kernel.h"
@@ -45,6 +46,11 @@ struct PsfCacheKey;
 
 }  // namespace detail
 
+/**
+ *  An exception thrown when we have an invalid PSF.
+ */
+LSST_EXCEPTION_TYPE(InvalidPsfError, lsst::pex::exceptions::InvalidParameterError, lsst::afw::detection::InvalidPsfError)
+
 /**
  *  A polymorphic base class for representing an image's Point Spread Function
  *
diff --git a/python/lsst/afw/detection/_psf.cc b/python/lsst/afw/detection/_psf.cc
index 5ddb43eb6..0fda6203b 100644
--- a/python/lsst/afw/detection/_psf.cc
+++ b/python/lsst/afw/detection/_psf.cc
@@ -28,6 +28,8 @@
 #include "lsst/utils/python.h"
 #include "lsst/utils/python/PySharedPtr.h"
 
+#include "lsst/pex/exceptions/Runtime.h"
+#include "lsst/pex/exceptions/python/Exception.h"
 #include "lsst/geom/Point.h"
 #include "lsst/afw/image/Color.h"
 #include "lsst/afw/table/io/python.h"  // for addPersistableMethods
@@ -51,6 +53,9 @@ void wrapPsf(utils::python::WrapperCollection& wrappers) {
     wrappers.addSignatureDependency("lsst.afw.image");
     wrappers.addSignatureDependency("lsst.afw.fits");
 
+    wrappers.wrapException<InvalidPsfError, pex::exceptions::InvalidParameterError>("InvalidPsfError",
+                                                                                    "InvalidParameterError");
+
     auto clsPsf = wrappers.wrapType(
             py::class_<Psf, PySharedPtr<Psf>, typehandling::Storable, PsfTrampoline<>>(
                 wrappers.module, "Psf"