diff --git a/FindFFTW.cmake b/FindFFTW.cmake
index 78b1194..350ce80 100644
--- a/FindFFTW.cmake
+++ b/FindFFTW.cmake
@@ -247,7 +247,7 @@ endif( FFTW_ROOT )
 
 #--------------------------------------- components
 
-if (FFTW_DOUBLE_LIB)
+if (FFTW_DOUBLE_LIB AND NOT TARGET FFTW::Double)
     set(FFTW_DOUBLE_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_LIB})
     add_library(FFTW::Double INTERFACE IMPORTED)
@@ -259,7 +259,7 @@ else()
     set(FFTW_DOUBLE_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_FLOAT_LIB)
+if (FFTW_FLOAT_LIB AND NOT TARGET FFTW::Float)
     set(FFTW_FLOAT_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_LIB})
     add_library(FFTW::Float INTERFACE IMPORTED)
@@ -271,7 +271,7 @@ else()
     set(FFTW_FLOAT_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_LONGDOUBLE_LIB)
+if (FFTW_LONGDOUBLE_LIB AND NOT TARGET FFTW::LongDouble)
     set(FFTW_LONGDOUBLE_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_LIB})
     add_library(FFTW::LongDouble INTERFACE IMPORTED)
@@ -283,7 +283,7 @@ else()
     set(FFTW_LONGDOUBLE_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_DOUBLE_THREADS_LIB)
+if (FFTW_DOUBLE_THREADS_LIB AND NOT TARGET FFTW::DoubleThreads)
     set(FFTW_DOUBLE_THREADS_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_THREADS_LIB})
     add_library(FFTW::DoubleThreads INTERFACE IMPORTED)
@@ -295,7 +295,7 @@ else()
     set(FFTW_DOUBLE_THREADS_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_FLOAT_THREADS_LIB)
+if (FFTW_FLOAT_THREADS_LIB AND NOT TARGET FFTW::FloatThreads)
     set(FFTW_FLOAT_THREADS_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_THREADS_LIB})
     add_library(FFTW::FloatThreads INTERFACE IMPORTED)
@@ -307,7 +307,7 @@ else()
     set(FFTW_FLOAT_THREADS_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_LONGDOUBLE_THREADS_LIB)
+if (FFTW_LONGDOUBLE_THREADS_LIB AND NOT TARGET FFTW::LongDoubleThreads)
     set(FFTW_LONGDOUBLE_THREADS_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_THREADS_LIB})
     add_library(FFTW::LongDoubleThreads INTERFACE IMPORTED)
@@ -319,7 +319,7 @@ else()
     set(FFTW_LONGDOUBLE_THREADS_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_DOUBLE_OPENMP_LIB)
+if (FFTW_DOUBLE_OPENMP_LIB AND NOT TARGET FFTW::DoubleOpenMP)
     set(FFTW_DOUBLE_OPENMP_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_OPENMP_LIB})
     add_library(FFTW::DoubleOpenMP INTERFACE IMPORTED)
@@ -331,7 +331,7 @@ else()
     set(FFTW_DOUBLE_OPENMP_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_FLOAT_OPENMP_LIB)
+if (FFTW_FLOAT_OPENMP_LIB AND NOT TARGET FFTW::FloatOpenMP)
     set(FFTW_FLOAT_OPENMP_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_OPENMP_LIB})
     add_library(FFTW::FloatOpenMP INTERFACE IMPORTED)
@@ -343,7 +343,7 @@ else()
     set(FFTW_FLOAT_OPENMP_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_LONGDOUBLE_OPENMP_LIB)
+if (FFTW_LONGDOUBLE_OPENMP_LIB AND NOT TARGET FFTW::LongDoubleOpenMP)
     set(FFTW_LONGDOUBLE_OPENMP_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_OPENMP_LIB})
     add_library(FFTW::LongDoubleOpenMP INTERFACE IMPORTED)
@@ -355,7 +355,7 @@ else()
     set(FFTW_LONGDOUBLE_OPENMP_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_DOUBLE_MPI_LIB)
+if (FFTW_DOUBLE_MPI_LIB AND NOT TARGET FFTW::DoubleMPI)
     set(FFTW_DOUBLE_MPI_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_MPI_LIB})
     add_library(FFTW::DoubleMPI INTERFACE IMPORTED)
@@ -367,7 +367,7 @@ else()
     set(FFTW_DOUBLE_MPI_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_FLOAT_MPI_LIB)
+if (FFTW_FLOAT_MPI_LIB AND NOT TARGET FFTW::FloatMPI)
     set(FFTW_FLOAT_MPI_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_MPI_LIB})
     add_library(FFTW::FloatMPI INTERFACE IMPORTED)
@@ -379,7 +379,7 @@ else()
     set(FFTW_FLOAT_MPI_LIB_FOUND FALSE)
 endif()
 
-if (FFTW_LONGDOUBLE_MPI_LIB)
+if (FFTW_LONGDOUBLE_MPI_LIB AND NOT TARGET FFTW::LongDoubleMPI)
     set(FFTW_LONGDOUBLE_MPI_LIB_FOUND TRUE)
     set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_MPI_LIB})
     add_library(FFTW::LongDoubleMPI INTERFACE IMPORTED)
diff --git a/FindMathGL.cmake b/FindMathGL.cmake
index ee5a2e0..cb87de8 100644
--- a/FindMathGL.cmake
+++ b/FindMathGL.cmake
@@ -24,7 +24,7 @@ find_library(MATHGL_QT5_LIBRARIES NAMES mgl-qt5 mgl2-qt5
   /usr/local/include
   )
 
-if(MATHGL_INCLUDE_DIR AND MATHGL_LIBRARIES)
+if(MATHGL_INCLUDE_DIR AND MATHGL_LIBRARIES AND NOT TARGET MathGL::Mgl AND NOT TARGET MathGL::Qt5)
   get_filename_component(MATHGL_LIBRARY_DIR ${MATHGL_LIBRARIES} PATH)
   set(MATHGL_FOUND TRUE)
   add_library(MathGL::Mgl INTERFACE IMPORTED)
diff --git a/FindQuadmath.cmake b/FindQuadmath.cmake
index 50f06b7..2b6cf23 100644
--- a/FindQuadmath.cmake
+++ b/FindQuadmath.cmake
@@ -31,7 +31,7 @@ int main(void){
 }" QUADMATH_FOUND)
   cmake_pop_check_state()
 
-  if (QUADMATH_FOUND)
+  if (QUADMATH_FOUND AND NOT TARGET QuadMath::QuadMath)
     set(QUADMATH_LIBRARIES "quadmath")
     set(HAVE_QUAD "${QUADMATH_FOUND}")
     add_library(QuadMath::QuadMath INTERFACE IMPORTED)